Interaction of a soliton with a local defect in a fiber Bragg grating

We study the interactions of a Bragg-grating soliton with a localized defect that is a combined perturbation of the grating and the refractive index of a fiber. A family of exact analytical solutions for solitons trapped by the deltalike defect is found. Direct simulations demonstrate that, up to the available numerical accuracy, the trapped soliton is stable at a single value of its intrinsic parameter theta. Depending on the parameter values, simulations of collisions between moving solitons and the defect show that the soliton can be captured by, pass through, or even bounce off the defect. If the defect is strong and the soliton is heavy enough, it may split into three fragments: trapped, transmitted, and reflected. (C) 2003 Optical Society of America.